1. Field of the Invention
The present invention relates to an improved method and associated apparatus for facilitating monitoring of an automated tool for one or more operational characteristics in order to detect undesired interference with the operation of the same and, more specifically, it relates to such method and apparatus which employs a wireless sensor such as a microelectromechanical systems device (MEMS) structured to transmit sensor information in space. In one embodiment, the wireless sensor is remotely energized through energy transmitted in space with the sensor rectifying the received energy into DC current and also receiving communications from a remote microprocessor while delivering communications of information originating within the sensor to the remote microprocessor. In another embodiment, the invention provides for wireless self-powered sensors which harvest energy from motion of the automated tool.
2. Description of the Prior Art
It has been known to employ various sorts of sensors in connection with the monitoring of conditions of operating equipment including industrial equipment employed to perform manufacturing functions on workpieces. In such systems the information from sensors is frequently delivered to a controller unit which may employ the sensor data to determine whether an output signal effecting a change in control of the equipment should be generated. See, generally, U.S. Pat. No. 6,101,857, the disclosure of which is incorporated herein by reference.
It has been known to employ microelectromechanical systems (MEMS) devices and associated sensors to detect the various properties such as, for example, vehicle tire pressure. It has also been known to employ sensors which react to acceleration limits employing an inertial response, the calibrated mass and the elastic response of at least part of the sensor geometry. The deflection of the elastic response may be coupled with hardware that utilizes another property to communicate a condition that can be acted upon by the system control.
It has also been known to transmit data and energy between a base unit and a remote station employing RF energy or other sources of energy in the transmission. See U.S. Pat. Nos. 6,289,237 and 6,615,074, the disclosures of which are expressly incorporated herein by reference.
For many uses in automated tools, it is not efficient to run wires or cables in order to energize and communicate with sensors which are monitoring portions of the automated tool for purposes of both protection and performance enhancement. The design of the automatic tool has to be altered to accommodate the same. Among other considerations, the size of the sensors as well as location which relates to distance between the sensor location and the site being monitored are taken into consideration. Further, the structural integrity of the automated tool and the required motion cannot be altered to accommodate sensors and any wiring employed therewith.
In spite of the foregoing teachings, there remains a meaningful need for an improved method of monitoring automated tools for undesired changes in operating properties of the system in order to facilitate prompt corrective action.